Diesel Generator Maintenance Protocol

Diesel generators are backup devices that provide power during utility power outages. Routine maintenance can extend the lifespan of your generator. Diesel generator maintenance is divided into weekly, monthly, and annual tasks. Let's learn more about the specific procedures for maintaining and servicing a diesel generator.

I. Weekly maintenance

1. Verify​ engine oil level between dipstick min/max marks. Top up with identical oil type if required.

2. Monitor​ diesel fuel level: ​drain​ tank water/sediment and ​inspect​ for leaks. Note: New fuel needs 24-hour settling.

3. Confirm​ coolant level (~5 cm below radiator cap neck). Add distilled water if low.

4. Test​ coolant heater operation (winter only).

5. Inspect​ air filter indicator; ​replace​ filter/element if red.

6. Measure​ battery charging voltage (auto units):

• 12V: ~14V normal
• 24V: ~27V normal

7. Clean the unit.

II. Monthly Maintenance:

The generator set should be operated under load for at least 30 minutes each month. The startup procedures and inspection items are as follows:

Before Starting the Generator Set:

1. Verify​ environment: Well-lit, ventilated, debris-free engine room. Implement noise-reduction measures.

2. Clear​ air intake/exhaust ducts of blockages.

3. Inspect​ radiator/engine for debris; ​secure​ loose/missing bolts/guards.

4. Test​ fan belt tension/wear; adjust/replace if required.

5. Confirm​ all instruments function accurately; repair/replace damaged units.

6. Tighten generator/control panel electrical connections.

7. Validate​ cooling water, lubricating oil, and diesel levels.

8. Scan​ unit for water, oil, air, or electrical leaks.

After starting the generator set:

1. Verify stable and normal operation.

2. Monitor oil pressure gauge: Maintain 3-6.5 bar range (smaller units: lower pressure; larger units: higher pressure). Select oil viscosity based on season/region.

3. Track coolant temperature: Keep between 70-90°C (varies with ambient temperature/load).

4. Confirm charging voltage: Maintain 2-3V above battery voltage.

5. Check the AC Output: Frequency, voltage, current.

8. Inspect for abnormal noise or new leaks; SHUT DOWN if detected.

9. Verify normal:

• Cylinder operation
• Coolant circulation
• Exhaust color (light grey)
  SHUT DOWN if abnormalities occur.

Generator set shutdown

It is divided into normal shutdown and emergency shutdown:

1. Normal Shutdown:​​

• Disconnect all electrical loads
• Allow 5-minute no-load cool-down period
• Shut down engine

2. Emergency Shutdown:​​
    Execute without delay when encountering:

• Flywheel mechanical failure
• Oil circuit blockage OR coolant temperature >100°C
• Abnormal noises / Loose flywheel / Transmission mechanism failure
• Sudden oil pressure drop (gauge needle rapid fall)

After the generator set shuts down:

1. Verify​ automatic transfer switch position (auto units only).

2. Inspect​ diesel tank level; refill if needed (allow 24h settling).

3. Review​ fault display; report required repairs.

4. Lubricate​ non-self-circulating components.

5. Log​ operational data; clean engine room/equipment.

6. Prepare​ pre-start checklist for next operation.

III. Annual Maintenance (Qualified Technician Required)​

1. Complete all weekly maintenance tasks plus the following:

2. Replace fuel filter; thoroughly drain/flush fuel tank.

3. Clean crankcase breather assembly.

4. Measure and adjust valve clearances per specifications.

5. Test all engine protection sensors and shutdown systems.

6. For generator component:

• Inspect housing for moisture/debris
• Clean internal components
• Megger-test winding insulation (record readings)
• Lubricate bearings per OEM guidelines

7. Conduct 2-hour load bank test at ≥30% capacity:

• Record all operational data
• Post-test: Replace engine oil and oil filter